The Neuropathology Core (Core C) has a central role in the Parkinson's Disease Research Center, it interacts closely with the Clinical Core and support the activities of all four projects. The goals of Core C are: 1) to arranges/conduct autopsies, establish diagnoses and delineate clinical pathological correlations in PD patients and age-matched controls evaluated in the Clinical Core and Project 1; 2) to provide well- characterized autopsy brain tissues for studies in projects 1-4; 3) to facilitate the pathological assessment of animal (mice) models relevant to PD and to perform and assist in quantitative morphological analyses of human and mice brains using state-of-the-art unbiased stereological approaches (Projects 1-4); and 4) to train physician/scientists in issues relevant to the neuropathology of PD and age-associated neurodegenerative disorders. The staff of Core C has experience with the pathological diagnoses, morphological studies, and quantitative morphometry of neurodegenerative disorders and has been responsible for many years for similar core functions in the JHMI Alzheimer's Disease Research Center. To accomplish its goals, Core C staffs and maintains the Brain Resource Center (BRC), a histology and immunocytochemistry (ICC) laboratory, and a quantitative morphometry and stereology facility. The BRC serves as a repository of fixed and frozen brain tissues prepared for research including bases of PD and controls. Through its many functions and facilities, Core C acts to support and coordinate the evaluation of clinical and experimental material, thereby contributing to key diagnostic and research activities of the PD Center.